Fusible link.



F. VOIGTMANN.

FUSLBLE LINK.

APPLICATION FILED MAY 23, 1910.

1,116,518, Patented Nov. 10, 1914.

TH i NORRIS PETERS co.. PHbTo-Ll'rh x, WASHINGTON. u.

UNITED STATES FRANK VOIGTMANN, OF CHICAGO, ILLINOIS.

FUSIBLE LINK.

Specification of Letters Patent.

Application filed May 23,

Patented Nov. 10, 1914. 1910. Serial No. 562,852. i

Y '0 all whom it may concern:

Be it known that I, FRANK VOIGTMANN, a

citizen of the United States, residing at Chi cago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Fusible Links, of which the following is a specification.

This invention relates to improvements in fusible links of the general type employed for automatically releasing fire doors, windows, etc., whenever the temperature rises above a predetermined height.

The salient object of the present invention is to provide a link which is less susceptible to becoming non-sensitive when coated with dust, calcimine, paint or the like, than those heretofore in use, while at the same time amply strong to sustain the draft or pull thereon, and of such construction that it may be very economically and uniformly manufactured, and by the use of comparatively cheap or unskilled labor.

The invention consists in the matters hereinafter described and more particularly pointed out in the appended claims.

In the drawings wherein I have shown a preferred embodiment of my invent1on- Figure l is a plan or top side view of a link embodying the invention; Figs. 2 and 3 are longitudinal and transverse sections taken respectively on lines 2- 2 and 3 -3 of Fig. 1. Fig. 4: is a cross sect1on on line d -t of Fig. 1. Figs. 5 and 6 are views of opposite sides of the blanks, devoid of solder.

The specific form of the sheetmetal parts of the preferred form of the link of my present invention was invented by myself some time ago, and is the subject of a pending application filed by me November 16, 1908, Serial No. 4562954. Parts of thelmks of that application were soldered together in the same general relation as that sh own in present application; the solder1ng having been performed by dipping the parts bodily, while held in proper assembled relation, into a molten bath of solder. This process re sulted in giving the entire exposed surface of the sheet metal parts a thin coating of solder and by demonstrations and tests, I determined that a link thus soldered and coated was more sensitive and reliable than where the soldering was performed by sim- 1y soldering the over-lapped meeting surfaces together without coating the remainder of the link. a

Since making the invention and discovery l above referred to, I have made a further disi covery which is apparently a paradox, in that have discovered that a link loaded and containing more metal and which would, therefore, apparently require a greater point is nevertheless more sensitive and re liable than one containing less metal. That is to say, I have discovered that by loading a link of this character with solder,that is, putting on a great excess in thickness of eration of the link are greatly enhanced. This condition applies and is true with espesulate it from the heat, as for example, when coated with calcnnme, whitewash, or soot.

now approved by the underwriters and is thebest construction now known to me, but the specific shape, the manner in which the overlapping parts are internested or dished together, and other minor details of construction may be varied without departing from my present invention.

Describing the link shown in the draw ings, each link is composed of two stampings, as 1 and 2, which may be and preferably are exact counterparts of each other; each stamping comprising a mutilated main central. ring portion 3 and an unmutilated smaller ring shaped loop or eyelet at formed integrally with the main ring. The main ring of each member is cut away at its side remote from its loop or eyelet portion 4 as indicated at in such manner that when the two links are assembled with their central main bodies in register, 27. (1., nested together, the loops or eyelet portions -i will project-at each end beyond the overlapped portions.

The overlapped portions obviously when soldered together, combine to a large extent the strength of both members, and in order that the eyelet portions 4, which are not overlapped may be approximately as strong as the overlapping portions I reenforce these smaller rings by eyeleting the openings thereof with metal eyelets as 6; these eyelets being provided with broad, underlying flanges 8, which fit inside the concave portions of the members 4, while their upper edges are cramped over the peripheries of the openings, as indicated at 7.

cial emphasis when the link has been coated w1thsometh1ng tending to protect it, or inamount of heat to become heated to a fusing solder at the parts which are to fuse and separate, the sensitlveness and reliabilityof op The construction of link shown herein is preferably soldered together by placing The stampings, eyeleted as described are them in properly assembled relation and gripping them between the jaws of a pair of tongs or pincers provided with point-ed teeth, so that their points of engagement with the link are small and, while thus held, are dipped bodily in a bath of molten solder. It will be understood, of course, that before thus soldering the parts, they all have been dipped in a suitable acid so as to take the solder readily.

Having thus assembled and soldered the parts together, I next proceed to load the links with additional solder. Conveniently, I apply this solder by the use of ahand soldering iron in the usual well known manner and take care to build up the solder very heavily across those parts of the link coincident with the edges of the overlapping parts, as indicated at 9 and 10. I alSO apply the solder thickly around the entire edges of the overlapped portions; the endeavor being to cover the joint at the edge of the overlapping portions thickly at all points. In practice, this results in filling up the interior of the concave central portion of the main link eyelet with solder.

Since my discovery of the supersensitiveness of a link so constructed, I have demonstrated the importance of thus loading the links with solder. The eculiar efiiciency or sensitiveness and reliability of the link is most pronounced when the link has been covered with a coating tending to insulate it from heat. The underwritersin testing such links coat them artificially with calcimine, whitewash, or the like, before subjecting them to a heat test; the purpose of this being to reproduce as nearly as ma be the adverse conditions to which such llnks are subject in actual practice. Such tests repeated many times by the underwriters have proven the importance of this new discovery,

so that they now insist that all links be thus heavily loaded with solder.

I claim as my invention:

1. A fusible link comprising two thin sheet-like members assembled in overlapping relation and forming when united a relatively fiat thin link, said members being entirely coated by readily fusible solder and provided with a thickened extra loading of solder at the separable joints.

2. A thin sheet-like fusible link comprisiing two sheet-like members stamped into similar intaglio relief configurations and nested together in partially overlapping relation, said members being united by readily fusible solder, completely covering the margins forming the joints between the overlapping portions and applied in heavy ex cess along and overlying the end margins of 2 the overlapping portions of said members, and said solder forming the exposed exterior surfaces at said joints.

3. A fusible link comprising two thin sheet-like members stamped into similar intaglio-relief configuration, partly overlapped and nested together as to said overlappmg portions, said members being entirely coated with readily fusible solder and united thereby and provided with athickened extra loading of solder overlying the margins along the separable joints between said overlapping arts;

4:. A usible link com rising two thin sheet-like members assemblisd in overlapping relation and formin when united a thin approximately flat lin ,said assembled members being completely coated b readily fusible solder and at the separab e joints addi tionally coated with a thickened extra loading of said readily fusiblesolder.

FRANK VOIGTMANN.

Witnesses:

ALBERT H. GRAVES, EMILIE ROSE.

Copies 0! this patent may be obtained for five cents each, by addressing the Commissioner o Eatonta,

Washington, D. G. 

